1. Field of the Invention
The present invention relates to a bone implant and, more particularly, to a bone implant that includes threads and that will not be removed after implantation into a bone.
2. Description of the Related Art
There is a wide variety of bone implants. Bone needles, bone nails, bone screws for locking implants, such as bone plates or artificial joints, intramedullary nails, or dental implants are common bone implants. Generally, the engagement stability between every type of bone implant and the bone is critical. A bone implant securely engaged with the bone can increase the medical effect and efficiency to be achieved.
Most of the bone implants are not removed after implantation into the bones. Taking a dental implant as an example, Taiwan Patent Publication No. 201121510 entitled “HUMAN BODY IMPLANT AND MANUFACTURING METHOD THEREFOR” focuses on improvement on the material of the surface of the dental implant. Taiwan Publication No. M338055 entitled “IMPROVED DENTAL IMPLANT STRUCTURE” focuses on the engagement reliability between the neck of the dental implant and the bone. Taiwan Publication No. M390130 entitled “ONE-PIECE ANGLE DENTAL IMPLANT” focuses on improvement on the abutment of the dental implant.
However, none of the above dental implants provides a thread with a structure capable of preventing sliding/disengagement movement in the reverse direction, such that the tooth implant that has implanted into an alveolar bone can only securely engage with the alveolar bone after the osseointegration between the bone tissues and the dental implant. In a case that the dental implant is subject to a force opposite to the thread direction during the osseointegration, the dental implant could have rotational movement and, thus, results in disengagement. Even the displacement is slight, the bone tissues could be loosened from the surface of the dental implant, leading to failure in the osseointegration. In view of the above reasons, improvement to the current bone implants is desired.